DensBits - circa 2014

Founded in 2007 and headquartered in Haifa, Israel - DensBits has
designed the world's first Memory Modem, a revolutionary technology created to
address the ever-increasing need for low-cost, high-performance NAND Flash-based
storage systems.

The company profile,
below, which I wrote exactly a year ago - is still the current picture today.
The only thing which has moved on since that was written is the state of the
SSD market's willingness and readiness to engage with this type of technology -
something which I discussed in another article -
Strategic
Transitions in SSD.

DensBits is an
SSD controller / IP
company which has been working on the problem of how to get better
data integrity
and reliability at
the SSD level when using new and future generations of high density
x3 MLC (TLC)
flash. The effects of scaling in these new memories presents a set of
characteristics which traditional SSD controller management techniques fail to
deal with effectively and economically.

At first glance DensBits's
technology looks like an impressive and clever way of viewing the problem and
efficiently dealing
with the vagaries of the flash bit data stream in a systematic way 
rather than bundling up a collection of ad-hoc schemes which might have
worked for SSDs in earlier memory generations  but which are independent
and conflict for the same CPU and capacity resources.

DensBits says that the combination of their techniques results in
significant gains in
endurance,
cost reduction
and performance
- when viewed at the system (whole SSD array level).

DensBits's
technology - which is available in controller and IP form offer utility in both
the consumer and enterprise SSD markets.

In a superficial way
DensBits's technology package looks similar to
Anobit,
STEC's CellCare and
Smart's Optimus.

But just as there are many different ways of doing wear leveling -
there are also
many
different twists on how to apply
adaptive R/W,
DSP ECC and information theory to the patterns of good and bad cells in a
flash array.

DensBits has created a complete IP suite - which includes
their own collaborative DSP, ECC and flash management instead of bolting
DSP onto a traditional suite of flash management tricks as an afterthought.

At
the SSD system level the benefits are additive and multi-dimensional.

Suppose you want to
optimize the SSD for speed - as in an enterprise product. He said that
DensBits enables you to get 60% faster write speeds. That's not (as you
might suppose) because of a parallel architecture or memory cycling trick. They
can do faster writes because their ECC is so strong - they can get away with
using shorter write pulses than traditional designs - and still reconstruct the
data reliably.

The DSP and flash manager learns from the ECC system
how good the flash pages are - and can deal with them adaptively. The bag of
memory modem tricks includes for example - using stronger and weaker codes in
different regions of the flash space. That gives more efficiency when it comes
to usable versus raw flash bits. And it's dynamically determined. Going back to
the faster writes thing... Shorter write pules place less stress on the memory
- so yielding better intrinsic reliability.

At the other end of the
market - the consumer end - the same IP suite can be set up to favor high
capacity (and lower performance) which optimizes power consumption and battery
life.

DensBits isn't the only company which says it can get good
results from cheap flash. There are others who also claim very high gains in
endurance (x10, x20 - and I've even seen claims of x100) from particular SSD
companies in the consumer, industrial and enterprise markets. But DensBits is
the only company I know of - which appears to have credible ambitions across
such a wide range of flash markets while using a single coherent IP set.
Specifically - DensBits says it would like to become the "ARM" of
the flash industry, providing reference designs for a wide range of
applications.

I asked - how does DensBits aim to sell its
technology?

I learned that the company is willing to license parts of
its SSD IP set to companies as diverse as flash memory makers, consumer SSD oems
and enterprise SSD oems.

In some markets the IP will be used to reduce
power consumption, in other it will increase capacity, or it can be used to get
better performance and reliability.

The interesting thing is that
DensBits has designed its licensing model around charging a percentage of the
ASP of the whole SSD (that's the sum of the controller and memory parts).

Finally
- on the naming of SSD
product names thing... The more I think about about the more clever I think
is the name that DensBits chose to describe what it offers - as the Memory
Modem. That's because one way to view the resources in a flash memory is as a
stream of bits which interact with the SSD controller.

I guess that
not many people will understand the nuances of that reference - because unless
you know about information theory and communications and noise - you don't get
the full message:-) But most people who will look at DensBits with a view to
using their technology (or figuring out where they stand in the competitive
landscape) will probably have enough of an electronics background to
appreciate the perspective they get on DensBits from this particular analogical
angle.

In April
2012 -
DensBits announced it
is sampling a new SSD controller - the
DB3610 -
which supports the latest 2Xnm and 1Xnm TLC (3 bits/cell ) MLC flash with an
extreme endurance
figure of more than 10K P/E cycles and R/W performance of up to 95MB/s / 65MB/s
and 4,000 / 1,100 R/W
IOPS (4KB),
for sequential and random operations, respectively.

InJune 2012- Seagate
announced it will use DensBits's flash care
technology in the design of forthcoming consumer and enterprise SSDs. Seagate
has also made an equity investment in DensBits.

When flash SSDs started to be used as
enterprise server accelerators in 2004 - competing
RAM SSD makers said
flash wasn't reliable
enough.

Since then flash has dominated the installed base of
enterprise SSD starting with SLC, followed by MLC, then a correction to eMLC
and now some SSD makers are saying TLC (x3) may be good enough.

But
it's not just the raw memory
type which determines the suitability of which flash can work reliably in
what type of enterprise SSD. The
controller IP and
cache architecture
can make a difference to the
endurance
of x5, x10, x20 - and I've even heard claims of x100...

That means TLC
(aka x3) - with the right SSD IP - may be as good as SLC in some types of
applications. And it costs a lot less and has higher capacity.

The interesting thing about
NVMdurance's IP is that it delivers endurance amplifying results using a
lightweight runtime controller. But this doesn't stop you getting even better
results by adding DSP correction as an additive process.

Editor:- January 2015 - Even if you already
thought that adaptive
R/W and DSP was an essential way for getting usable SSDs out of smaller 2D
nand flash - then there are even more reasons for using this technology on the
journey in 3D.

Among other
things in this paper:- DensBits says that the scope for inter-cell interference
grows from 8 identifiable routes in 2D to 26 for each cell in 3D.

But
memory modem technology (DensBits's branding for their collection of adaptive
R/W DSP IPs) will (over and above everything it already does for 2D)
intelligently decouple read operations according to the severity of read
operations expected in the new 3D architectures - and even supports the notion
of TLC (x3) within 3D. (Which "needs state of art decoder and signal
processing".)

"When I spoke to
Amir Tirosh at DensBits in April, 2012 I knew within a few
minutes that DensBits would be a company which would go straight from stealth
mode into the Top SSD Companies List - within the same quarter..."

Editor:- June 25, 2012 - Seagate announced
today it will use DensBits's
flash care technology in the design of forthcoming consumer and enterprise SSDs.

Seagate
has also made an equity investment in DensBits.

Editor's
comments:- I've already written more than enough about about this technology
trend recently on the home page.

As DensBits told us a few months ago - their business plan is work
with companies which sell complete SSDs - instead of licensing their technology
to other controller
makers. DensBits's technology spans the widest spectrum of adaptive DSP flash
SSD applications from consumer and industrial to fast-enough enterprise SSDs.

If Seagate leverages DensBits's flash technology successfully - the
result will be tougher competition for companies like
SanDisk in the
consumer SSD market
and tougher competition for
STEC and
SMART in the
fast-enough
enterprise SSD market.

..

..

"....nobody really
knows how long NAND can keep scaling. So we have to keep trying and we have
to be innovative. But we are aggressively working on the future NAND, future
technologies beyond NAND...."

Editor:- April 30, 2012 - DensBits today
released a new SSD controller - the
DB3610 -
which supports the latest 2Xnm and 1Xnm TLC (3 bits/cell ) MLC flash with an
extreme endurance
figure of more than 10K P/E cycles and R/W performance of up to 95MB/s / 65MB/s
and 4,000 / 1,100 R/W
IOPS (4KB),
for sequential and random operations, respectively.

Editor's comments:- It's easy to miss the
significance of new SSD products and technologies. And you might think from
looking at the text and numbers above - this is a consumer style
SSD controller - and
it's not for me.

But I think DensBits may become one of the
top 20 SSD companies
real soon - unless it gets acquired before that happens.

...

Its flash technology has very high
roadmap symmetry
and the potential to impact competitiveness in the consumer, embedded and
fast-enough enterprise SSD markets with a splash that's as big as
SandForce made when
it emerged on the scene 3 years ago.

...Later:- guess what? - in the first 10 days of May 2012 - search volume
for readers following up DensBits propelled them into the top 5 SSD companies -
in line with my prediction above.